Surge reliever relief valve

ABSTRACT

A surge reliever relief valve is provided in which a flexible membrane is maintained in a peripherally sealed relationship across a rigid grid. The grid bounds the laterally adjacent intake and output regions of the valve. Intake pressure extends the membrane allowing flow between intake and output. Extension of the membrane is limited by a retainer. Extension may be elastic or inelastic.

CROSS REFERENCE TO RELATED APPLICATION

This application is a continuation-in-part of U.S. patent applicationSer. No. 264,220, filed Oct. 28, 1988, now U.S. Pat. No. 4,949,750.

FIELD OF THE INVENTION

This invention pertains to liquid surge relief valves and moreparticularly to a relief valve having a peripherally supportedmembrane-like seal interposed between a rigid grid plate and a retainer.

BACKGROUND OF THE INVENTION

Pressure surges or water hammer phenomena are caused by liquiddeceleration or flow variations in pipes. The resulting destructiveenergy can cause ruptures in piping and piping components, pipevibrations and noise. Surge arresters or relief valves, if properlyused, provide relief to increases in fluid pressure associated withunsteady flow conditions. While other relief means or desurgers areknown, the present invention is designed to operate reliably andeconomically.

SUMMARY OF THE INVENTION

The benefits and improvements of the present invention are provided by avalve having separate laterally adjacent intake and output regionsbounded by a grid and sealable from one another by a membrane supportedby the grid. The membrane is interposed between the grid and a retainerwhich defines the arched interior of a flow chamber. Pressure surgesdeflect or distend the membrane against pressure communicated from apressure chamber to the flow chamber.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows in cross section, a surge relief valve of the presentinvention;

FIG. 2 shows in plan view the grid plate utilized in the valve of FIG.1;

FIG. 3 shows the grid plate of FIG. 2 in cross section;

FIGS. 4-6 show in sequential schematic diagrams, the operation of thevalve illustrated in FIG. 1;

FIG. 7 shows another embodiment of the relief valve of the presentinvention;

FIGS. 8-10 show in sequential schematic diagrams, the operation of thevalve illustrated in FIG. 7; and

FIGS. 11-18 illustrate a surge relief valve forming a third embodimentof the present invention.

DETAILED DESCRIPTION

As shown in FIG. 1, the surge reliever relief valve 10 of the presentinvention comprises a "T" shaped section of pipe 11 defining a valvebody having an intake flange 12, an output flange 13 and a third flange14, onto which the mechanically active components of the invention aremounted. The "T" section or valve body 11 further includes a barrier 15which transects the valve body and separates the intake portion 16 fromthe output portion 17 of the valve. The intake region 16 includes aneffluent end 61 where fluid flow traverses the opening defined by thethird flange. The output region 17 includes an affluent end 62 wherefluid enters the region 17 from the opening defined by the third flange.Together, the affluent of the output and effluent end of the intakecomprise a divided or transected opening. It should be understood thatin operation, the valve described herein is functionally symmetrical andthat the intake and output designations used herein are made forconvenience, and may be determined by the direction of flow. Deflectors18, 19 are positioned within the intake and output portions to improvethe efficiency of flow. Through passages 20 are provided around theedges of the deflectors so that a pressure differential across thedeflector is prevented.

The third flange 14 supports a gasket 21, a grid (in this instance agrid plate) 22 and the flange 41 of a cap 23. A flat elastomericmembrane 24 is interposed between the grid and the cap flange. The cap23 is divided by an arched retainer 25 into a flow chamber 26 and apressure chamber 27. The pressure chamber includes upstanding side walls29, one or more pressure ports 30 and a dome 31. Vents 28 extend betweenthe pressure chamber and the flow chamber allowing pressure in thechamber to bear on the membrane. In this instance, the retainer 25 andflat grid plate 22 define a hemispherical flow region 26.

As illustrated in FIGS. 2 and 3, the grid plate 22 may comprise aperipheral flange 32 having a pattern of bolt holes 33 which accommodatethe fasteners 34 which attach the cap 23 to the third flange 14 of the"T" 11. In the alternative, the grid can be incorporated integrally intothe valve body, as by welding. A recessed landing 35 accommodates themembrane 24 and bears a second pattern for bolt holes 36 which are usedin the securing of the grid 22 to the third flange 14. A central portionof the grid includes a series of ribs 37 extending from a central pier38 to the landing area 35, thus defining laterally adjacent input andoutput matrices, each having through passages 39. The central pier 38has bolt holes 40 which are used to affix the pier to the barrier 15 inthe valve body. Thus, passages 39 in the intake matrix cover and acceptflow from the intake effluent, while passages in the output matrix admitflow to the output affluent.

When assembled, as seen in FIG. 1, the grid 22 is sandwiched between thecap flange 41 and the third flange 14. The gasket 21 seals between thegrid and the flange 14. The elastomeric membrane 24 seals between thecap flange 41 and the grid 22. The membrane 24 is sealed about itsperiphery or circumference by the clamping action of the flanges 41, 14.The membrane is said to cover the opening to the flow chamber.

Thus, it can be appreciated that when the cap 23 is pressurized with dryair or nitrogen through the ports 30, that the membrane 24 acts as aclosure which resists the flow of liquid in the valve from the intakesection 16 to the output section 17. Generally, a fixed pressure of atleast 10 p.s.i. in excess of line pressure is maintained in the pressurechamber. However, the pressure in the pressure chamber may be modulatedin accordance with variations in line pressure which are not consideredsurges. As shown in FIGS. 4, 5 and 6, when the pressure of fluid in theintake section 16 exceeds the pressure in the cap 23 the membrane 24will expand or extend, gradually increasing the effective volume of theintake 16 by allowing fluid to expand into the opening of the flowchamber 26 (FIG. 4), eventually communicating the intake 16 and output17 (FIG. 5), and finally allowing full flow between intake 16 and output17 (FIG. 6). As shown in FIG. 6, in the fully extended position, themembrane is in full contact with the retainer and is prevented fromfurther expansion by the generally hemispherical retainer 25.

A second embodiment of the invention is illustrated in FIGS. 7-10. Thisembodiment of the invention is well suited to higher pressureapplications because the sealing membrane is inelastic, i.e., notextensible to any appreciable degree. Rather than a flat grid plate, agrid 50 having a gentle curvature is provided. The curvature of thearched retainer 60 is similar to that of the grid. The radius 51 of thecurvature of the grid is preferably greater than the radius 52 of thedivided opening. Thus, the similar curvatures of the grid 50 and archedretainer 56 define a lenticular flow chamber 53. Rather than a flatextensible membrane, a reinforced polymeric membrane 54 is provided,whose rest shape matches the curvature of the grid 50. The reinforcementof the polymeric membrane can be by way of loosely woven nylon or rayoncloth that renders the membrane flexible but inelastic.

Under fluid pressure which exceeds the relief pressure in the cap 55,the reinforced membrane rolls or folds, as shown in FIG. 8. Membranestretching in this instance is minimal. Continued membrane deflectionadmits partial flow into the output affluent as shown in FIG. 9,eventually contacting the retainer in full as shown in FIG. 10. Thecurvature of the arched portion 56 of the cap matches the curvature ofthe grid 50, so that even in the full flow position, as shown in FIG.10, the membrane 54 is not significantly deformed.

With reference now to FIGS. 11-18, a surge reliever relief valve 100forming a third embodiment of the present invention is illustrated. Thevalve includes an inlet flange 102, a tee 104 and an outlet flange 106.Inlet flange 102 and outlet flange 106 are welded to the tee 104 as bestshown in FIG. 11. A barrier 108 is secured within the tee and separatesthe intake portion 110 from the output portion 112. Deflectors 114 and116 are mounted in the tee to improve the efficiency of the flow throughthe valve.

As best seen in FIGS. 11-13, and 17, a bottom body flange 118 is weldedto the tee. A grid plate 120, best seen in FIGS. 13, 14 and 15, iswelded within the flange 118. The body flange and grid plate cooperatewith the tee and barrier 108 so that fluid flowing through the valvemust pass through the ports 122 of the grid plate at the effluent end124, through flow chamber 126 and into the ports 128 at the affluent end130. On its upper surface, the flange 118 defines a circular recess toreceive reinforced polymeric membrane 54. At the outer perimeter of theflange are bolt holes 134.

A top body flange 136 has similar bolt holes 138 formed therein whichalign with the bolt holes 134 so that flanges 118 and 136 can befastened together. Within the top body flange 136 is welded a vent plate140 as best seen in FIGS. 17 and 18. Vent plate 140 has fivethree-eighth inch diameter vent holes 141 formed therein, one hole alongthe central axis of the vent plate and the other four distributeduniformly about the center line at a pre-determined radius.

A dome 142 having pressure ports 144 is welded atop the top body flange136 to form a pressure chamber 146.

An elastomer support ring 148, illustrated in FIG. 16, is used incooperation with the bottom body flange 118 to confine the polymericmembrane 54. The membrane 54 is a non-extensible member, withreinforcement of the polymeric membrane by way of loosely woven nylon orrayon cloth that renders the membrane flexible, but inelastic. Themethod of operation of the relief valve 100 is substantially identicalto the valves described previously.

While the principles of the instant disclosure are provided by way ofspecific examples, it will be understood that these examples should notoperate as limitations to the scope of the invention as set forth in thefollowing claims.

I claim:
 1. An improved surge relief valve, comprising:a valve bodyhaving an intake region, an output region and a portion defining acylindrical opening; a barrier mounted in the valve body to separate theintake region from the output region within the valve body, the barrierextending to an end at the opening and bisecting the opening to definean effluent end and an affluent end; a body bottom flange welded to thevalve body over the opening, said bottom body flange having a grid platewith a recessed landing and a central portion, the central portionhaving a concave shape with a center pier extending along the end of thebarrier and a plurality of ribs extending between the pier and recessedlanding to define a first set of passages over the effluent end and asecond set of passages over the affluent end; a membrane of a flexible,non-extensible material sealed to the recessed landing of the grid plateabout the central portion and covering the passages in its rest positionto isolate the effluent and affluent ends; a top body flange mounted tothe bottom body flange, said top body flange having a vent plate thereinwith a concave shape and having a plurality of pressure ports formedtherethrough, the grid plate and vent plate forming a flow chambertherebetween; a dome welded to said top body flange and forming apressure chamber, the pressure ports opening into the pressure chamber.2. An improved surge relief valve, comprising:a valve body having anintake region, an output region and a portion defining a cylindricalopening; a barrier mounted in the valve body to separate the intakeregion from the output region within the valve body, the barrierextending to an end at the opening and bisecting the opening to definean effluent end and an affluent end; a body bottom flange welded to thevalve body over the opening, said bottom body flange having a grid platewith a recessed landing and a central portion, the central portionhaving a concave shape with a center pier extending along the end of thebarrier and a plurality of ribs extending between the pier and recessedlanding to define a first set of passages over the effluent end and asecond set of passages over the affluent end; a membrane of a flexible,non-extensible material sealed to the recessed landing of the grid plateabout the central portion and covering the passages in its rest positionto isolate the effluent and affluent ends; a top body flange mounted tothe bottom body flange, said top body flange having a vent plate thereinwith a concave shape and having a plurality of pressure ports formedtherethrough, the grid plate and vent plate forming a flow chambertherebetween; a dome welded to said top body flange and forming apressure chamber, the pressure ports opening into the pressure chamber;and an elastomer support ring for supporting the membrane within therecessed landing of the bottom body flange.